The present invention relates generally to vehicular diagnostic systems and particularly to a vehicular diagnostic system employing a portable communications control station.
With the advent of motor vehicles being equipped with computer control systems by the manufacturer, the repair of malfunctions has become substantially more sophisticated than in the past. In order for the vehicle computer to properly perform its control function, it typically interrogates a variety of sensors which are used to monitor various vehicle operating parameters. In several of these vehicle computer systems, as many as twenty or more sensors are employed for control purposes and to assist on-board diagnosis by the vehicle computer so that an immediate warning may be displayed to the vehicle operator. Examples of such vehicle computer systems are disclosed in the Kastura, et al., U.S. Pat. No. 4,277,772 issued on July 7, 1981, and the Baumann, et al., U.S. Pat. No. 4,267,569 issued on May 12, 1981, which are both hereby incorporated by reference.
In many vehicle models, means for obtaining direct access to the monitored parameter data on a real time basis is installed at the factory so that various display tools, engine analyzers and so forth may be used to facilitate a more complete diagnosis than that provided by the vehicle computer. For example, in many General Motors vehicle models, an Assembly Line Communications Link (ALCL) terminal is installed under the dashboard of the vehicle in the passenger compartment. This ALCL terminal is connected to an input/output (I/O) port of the vehicle computer or electronic control module (ECM) so as to permit the transmission of the monitored parameter data to the ALCL terminal upon the reception of the appropriate data enable signal at the ALCL terminal.
In the past, hand held display tools have been employed to selectively display the value or status of individual parameters. An example of such display tools are the "Mini-Scanner" model 5247 and the "Multi-Scanner" model 3818 display tools marketed by Micro Processor Systems, Inc., Sterling Heights, Mich. Each of these tools provide one connector which is used to obtain the parameter data from the ALCL terminal and another connector which is adapted to draw electrical power from the vehicle cigarette lighter. These tools also provide switches to adjust the tool to the appropriate vehicle model and select the parameter desired to be displayed on the light emitting diode (LED) display of the tool. Additionally, a "Video Scanner" circuit designed by Micro Processor Systems, Inc., for use in connection with an engine analyzer console has been employed to simultaneously display all of the parameter data available on the cathode ray tube (CRT) of the engine analyzer.
While the above-identified display devices have been found to be very effective in assisting the diagnosis of the engine and other vehicle systems by the automotive mechanic, the need exists to have the capability of employing the substantial computer power of a remote large scale data processor to analyze a variety of problems associated with a vehicle. Additionally, it is well known in the art that many vehicle problems or malfunctions occur intermittently or occur only under actual driving conditions. Thus even if the capabilities of a remote data processor are to be utilized, the need exists for a diagnostic system which is capable of collecting the parameter data during actual driving conditions and subsequently transferring this data to a remote data processor for analysis.
Accordingly, it is a principle objective of the present invention to provide a communications control station for a vehicular diagnostic system which is capable of both recording and transmitting vehicle parameter data to a remote data processor station.
It is another objective of the present invention to provide a communications control station which is capable of both transmitting and receiving voice and data communications.
It is a further objective of the present invention to provide a communications control station which is portable and is adapted to derive all of its operating power from the vehicle.
It is an additional objective of the present invention to provide a portable communications control station which is capable of checking the validity of the parameter data being recorded and/or transmitted.
It is yet another objective of the present invention to provide a portable communications control station which is capable of servicing a variety of vehicle models over a number of model years.
It is yet a further objective of the present invention to provide a portable communications control station which is capable of transmitting recorded or real time parameter data to the remote data processing station from inside the vehicle.
It is yet an additional objective of the present invention to provide a portable communications control station which is capable of employing a commercial display device for displaying selected parameter values, even while the parameter data is being recorded and/or transmitted to the remote data processor.
It is still another objective of the present invention to provide a vehicular diagnostic system in which telephone communication can be initiated at either the portable communication control station or the remote data processor station.
It is still a further objective of the present invention to provide a vehicular diagnostic system in which at least one electronically controlled device in the vehicle can be operated at the remote data processor station.
To achieve the foregoing objectives, the present invention provides a vehicular diagnostic system which generally comprises a portable communications control station and a remote data processor station. The control station includes a portable communications controller which comprises means for connecting the controller to a vehicle data link terminal capable of supplying parameter data monitored by the vehicle computer, means for connecting the controller to a source of electrical power in the vehicle, microcomputer means for enabling the flow of the parameter data through the data link terminal and for composing the data parameter data into a predetermined data stream, means for recording the data stream, and means for connecting the controller to a telephone line and for transmitting the data stream through the telephone line to the remote data processor station. Both the control station and the remote data processor station include telephone communication means for enabling both voice and data communication transfer on an alternative basis between the control station and the data processor station.
The present invention also provides a method of transferring parameter data, which generally comprises the steps of enabling the flow of the parameter data to the controller, composing the data into a predetermined data stream having at least one word for permitting the validity of the parameter data to be determined, and recording the data stream on magnetic tape. This method also includes the steps of playing back the recorded data stream, determining the validity of the recorded parameter data, and transmitting this data through a telephone line to the remote data processing station.